Process of devulcanizing caoutchouc, india-rubber, &amp;c.



UNITED STATES PATENT OFFICE.

ALBERT EDWARD JENS VALDEMAR JOHAN THEILGAARD, OF COPEN- HAGEN, DENMARK.

PROCESS OF DEVULCANIZING CAOUTCHOUC, INDIA-RUBBER, 8L0.

SPECIFICATION forming part of Letters Patent No. 642,764, dated February 6, 1900.

Application filed June 1, 1899. Serial No. 719,020. (No specimens.)

The following is an example of the above-- mentioned process: Vulcanized oaoutchouc, divided into pieces of a suitable size, is placed in a recipient adapted for the purpose and is therein treated with a solution of cyanid of potassium or other cyanid in proportion to the amount of sulfur contained in the material subjected to the treatment. In order to accelerate the process, the temperature may be raised by means of direct or indirect steam.

When the devulcanization is finished, the solution is removed and the material is washed and carefully dried. The devulcanized caoutchouc can now be formed into new articles and again devulcauized.

Having now particularly described and ascertained the nature of the said invention and in what manner the same is to be performed, I declare that what I claim is- The process of devulcanizing caoutchouc, india-rubber, gum-elastic, and similar materials, characterized by the said materials,after being divided into pieces of suitable size, being placed in a recipient and treated with a solution of a cyanid, eventually under a raised temperature, whereupon the materials, after a thorough devulcanizing, are removed from the solution, washed, and dried.

Signed at Copenhagen, Denmark, this 20th day of May, 1899.

ALBERT EDWARD JENS VALDEMAR JOHAN TIIEILGAARD.

Witnesses:

P. HOFMAN BANG, JULEs BLONG. 

